1. Field of the Invention
The present invention pertains to apparatus for limiting the insertion of a tube-like carton blank onto a mandrel. More particularly, the present invention relates to a single carton stop assembly associated with a turret which carries a plurality of tube-receiving mandrels between carton-forming stations disposed about the mandrels.
2. Description of the Prior Art
Machines for the automated fabrication of gable-top cartons formed from blanks of paperboard or the like material are well-known in the art. The more popular types of carton-forming stations typically include a hub or turret carrying a plurality of spaced radial mandrels. A plurality of work stations for carrying out operations on a carton blank are disposed about the mandrels at various radial positions. The carton-forming sequence is initiated at a first station where flattened carton blanks are opened and inserted onto a mandrel, the mandrel thereafter being rotated through a succession of stations which perform a variety of operations on the carton blank.
Machines of this type frequently have a number of moving assemblies in motion about the turret. For example, a stripper system reaches toward a mandrel containing a fully formed carton, to extract the carton therefrom. Conveyor systems are in motion about the turret to position formed cartons into an array which is carried downstream to subsequent stations for filling, and sealing, for example. It is therefore generally undesirable to require an operator to reach into and around the turret, and particularly adjacent the mandrels of the turret, which are constantly being indexed from station to station. Further, even if otherwise desirable, access to the mandrels is restricted in that several closely-spaced turrets are usually ganged together, on a common shaft.
Frequently, a single carton-forming and filling assembly line will be relied upon to accommodate a variety of carton sizes throughout a typical production period. One adjustment that must be made upon changeover to accommodate cartons of different lengths, is that assemblies for limiting the amount of insertion of a carton tube onto the mandrels must be adjusted, since the bottom portions of carton blanks of different lengths must all be similarly aligned adjacent the free end of the mandrel. Similar alignment is required, since the same bottom-forming operations are performed, regardless of carton size.
As can be seen from the above, it is undesirable to have an operator contact the mandrels to adjust any carton stops that may be mounted thereon. An example of this stop member arrangement is given in U.S. Pat. No. 4,456,118 issued June 26, 1984, to Kauffman et al. In this type of arrangement, carton stops on each mandrel of a turret must be adjusted when a different size carton is run through an assembly line. Not only must the machine be temporarily halted during such adjustment, but also there is always the risk that the machinery may be inadvertently activated while the operator is reaching into the interior of the turret mechanism.